WGU C959 DISCRETE MATH EXAMINATION
TEST 2026 FULL QUESTIONS AND
SOLUTIONS 100% CORRECT
⩥ Matrix multiplication size. Answer: # of columns of matrix A must be
the same as the # of rows of matrix B; otherwise undefined
(m * n) * (n * p) = (m * p)
⩥ Matrix multiplication process. Answer: Performed by multiplying the
elements of each row of the first matrix by the corresponding elements
(i.e. same index) of each column of the second matrix. Add the products.
(Row-column rule)
⩥ Invertible matrix (nonsingular matrix). Answer: A square matrix that
has an inverse
If AB = BA = Identity matrix, A and B are inverse matrices
⩥ Singular matrix. Answer: a square matrix that does not have an
inverse
, ⩥ If a matrix has a row or column with all 0s?. Answer: Matrix is
singular
⩥ Coefficient matrix. Answer: a matrix that contains only the
coefficients of a system of equations
⩥ Augmented matrix. Answer: a coefficient matrix with an extra column
containing the constant terms
⩥ Transpose of a transpose. Answer: (A^T)^T=A; reverts to same matrix
⩥ Solving matrix equations using inverse matrices. Answer: x = A^-1 *
b
x = variables
b= constants
⩥ Elementary Row Operations. Answer: 1. (Replacement) Replace one
row by the sum of itself and a multiple of another row.
2. (Interchange) Interchange two rows
3. (Scaling) Multiply all entries in a row by a nonzero constant
⩥ Elementary matrices. Answer: Identity matrix that has had the desire
elementary row operation performed on it.
TEST 2026 FULL QUESTIONS AND
SOLUTIONS 100% CORRECT
⩥ Matrix multiplication size. Answer: # of columns of matrix A must be
the same as the # of rows of matrix B; otherwise undefined
(m * n) * (n * p) = (m * p)
⩥ Matrix multiplication process. Answer: Performed by multiplying the
elements of each row of the first matrix by the corresponding elements
(i.e. same index) of each column of the second matrix. Add the products.
(Row-column rule)
⩥ Invertible matrix (nonsingular matrix). Answer: A square matrix that
has an inverse
If AB = BA = Identity matrix, A and B are inverse matrices
⩥ Singular matrix. Answer: a square matrix that does not have an
inverse
, ⩥ If a matrix has a row or column with all 0s?. Answer: Matrix is
singular
⩥ Coefficient matrix. Answer: a matrix that contains only the
coefficients of a system of equations
⩥ Augmented matrix. Answer: a coefficient matrix with an extra column
containing the constant terms
⩥ Transpose of a transpose. Answer: (A^T)^T=A; reverts to same matrix
⩥ Solving matrix equations using inverse matrices. Answer: x = A^-1 *
b
x = variables
b= constants
⩥ Elementary Row Operations. Answer: 1. (Replacement) Replace one
row by the sum of itself and a multiple of another row.
2. (Interchange) Interchange two rows
3. (Scaling) Multiply all entries in a row by a nonzero constant
⩥ Elementary matrices. Answer: Identity matrix that has had the desire
elementary row operation performed on it.
